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CVE-2025-40173

HIGHCVSS 7.8/10EPSS 0.19%

Last modified

CVE-2025-40173 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: net/ip6_tunnel: Prevent perpetual tunnel growth Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: net/ip6_tunnel: Prevent perpetual tunnel growth Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.19%

9.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 566f8d5c8a443f2dd69c5460fdec43ed1c870c65; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 11f6066af3bfb8149aa16c42c0b0c5ea5b199a94; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 402b6985e872b4cf394bbbf33b503947a326a6cb; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 10fe967efe73c610e526ff7460581610633dee9c; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 48294a67863c9cfa367abb66bbf0ef6548ae124f; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < eeb4345488672584db4f8c20a1ae13a212ce31c4; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < b6eb25d870f1a8ae571fd3da2244b71df547824b; >= 8eb30be0352d09165e94a41fef1c7b994dca0714, < 21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16
LinuxLinux4.7

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2025-40173?
In the Linux kernel, the following vulnerability has been resolved: net/ip6_tunnel: Prevent perpetual tunnel growth Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer.
How severe is CVE-2025-40173?
CVE-2025-40173 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2025-40173?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST